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Custom functions

CF explained

Most EOS digital cameras offer custom functions. These allow you to alter the way the camera operates to suit your own personal needs. Exposure, focusing and flash are just some of the areas covered by the functions. Each function has a factory-defined default setting, plus one or more alternative settings.

Custom functions are set through the camera menu system. Find and select ‘Custom Functions’ and you will bring up a screen with each custom function number displayed. Select the appropriate number and you will be taken to a screen where you can select from the various options for that custom function.

The display will usually indicate which functions are no longer at their default setting. You can either go to each function to change the setting, or go to the ‘Clear Setting: menu option’ to reset all the custom functions to the default settings.

On some models, it is possible to register up to three groups of custom function settings. This means you can change a number of different custom functions and save all these change under one group registration. This saves you the time and trouble of going through and changing each custom setting individually the next time you want to use the same set. You could, for example, have one group of settings for landscape photography, and another for sports shooting.

The number of custom functions varies from camera to camera, as does the reference number for a particular function. However, the list below, for the EOS-1D Mark II and EOS-1Ds Mark II, gives a guide to the type of camera functions that can be changed.

A specific custom function is usually written as C.Fn.-XX-Y, where the first number (XX) is the custom function reference, and the second number (Y) is the selected option within that function. The default setting for each custom function is usually ‘0’. So custom function 12 (mirror lockup) is written as either C.Fn.-12-0 (lockup disabled) or C.Fn.-12-1 (lockup enabled).

Popular professional CF settings

00 Focusing Screen
Adjust to suit the type of focusing screen fitted.
  1. N Ec-N, R
  2. L Ec-A, B, C, C II, C III, D, H, I, L
01 Viewfinder Display During Exposure
  1. Disable (no display in viewfinder during continuous shooting)
  2. 1 Enable (displays exposure information and number of remaining shots during continuous exposure)
02 Shutter Release without Card
  1. Enable (shutter fires without card in camera)
  2. Disable (shutter will not fire without card in camera)
03 Unused
04 Shutter Button/AE Lock Button
Assigns actions of shutter button and AE lock button.
  1. AF/AE lock
  2. AE lock/AF
  3. AF/AF lock (no AE lock)
  4. AE/AF (no AE lock)
05 Manual Tv/Av Set. for Manual Exposure
Assigns actions of main dial and quick control dial
  1. Tv: Main Dial, Av: Quick Control Dial
  2. Tv: Quick Control Dial, Av: Main Dial
  3. Tv: Main Dial, Av: Quick Control Dial (available with the lens detached)
  4. Tv: Quick Control Dial, Av: Main Dial (available with the lens detached)
06 Exposure Level Increments
Adjusts level of exposure and exposure compensation increments.
  1. 1/3-stop, exposure compensation 1/3-stop
  2. Full-stop, exposure compensation 1/3-stop
  3. 1/2-stop, exposure compensation 1/2-stop
07 USM Lens Electronic Manual focusing
  1. After in-focus: Enable
  2. After in-focus: Disable
  3. Disable
Only applicable with certain lenses.
08 Top LCD Panel/Rear LCD Panel
Changes the information displayed.
  1. Number of remaining shots/file number
  2. ISO/number of remaining shots
  3. ISO/file number
  4. Number of images saved in the folder/ Number of remaining shots
09 Bracketing Sequence/Auto Cancel
Changes the bracketing sequence and determines whether the sequence is repeated for the next shot, or cancelled.
  1. 0 − + /Enable
  2. 0 − + /Disable
  3. − 0 + /Enable
  4. − 0 + /Disable
10 AF Point Illumination upon Focusing
  1. Lights (dimmed)
  2. Does not light
  3. Lights (not dimmed)
  4. Lights brightly
11 AF Point Selection Method
  1. Left/Right: AF point selector + Main Dial
    Up/Down: AF point selector + Quick Control Dial
  2. Left/Right: Exposure compensation button + Main Dial
    Up/Down: Exposure compensation button + Quick Control Dial
  3. Left/Right: Quick Control Dial only
    Up/Down: Assist button + Main Dial
  4. Left/Right: FEL button + Main Dial
    Up/Down: FEL button + Quick Control Dial
12 Mirror Lockup
When enabled, first press of shutter button locks mirror in up position’ second press of button fires shutter and release mirror.
  1. Disable
  2. Enable
13 Number of AF Points/Spot Metering
Changes the number of focus points used.
  1. 45 points/center
  2. 11 points/linked to the active AF point
  3. 11 points/center
  4. 9 points/linked to the active AF point
14 E-TTL II autoflash system
Changes the metering pattern used for flash metering.
  1. Evaluative
  2. Average
15 Shutter Curtain Synchronisation
Set the flash to fire just after the shutter opens (first curtain), or just before the shutter closes (second curtain).
  1. 1st-curtain sync.
  2. 2nd-curtain sync.
16 Safety Shift Setting
In Tv and Av modes, the safety shift setting allows the pre-selected aperture or shutter speed to be changed by the camera if a sudden change in subject brightness renders the exposure unsuitable.
  1. Disable
  2. Enable
17 AF Point Activation Area
Expands the AF point activation area by one point around the manually-selected point, making a total of seven points active. With the automatic option, 7 or 13 points become active, depending on the lens focal length and the AF mode.
  1. Disable
  2. Expands by one point (7 points)
  3. Expands automatically (max. 13 points)
18 Switch to the Registered AF Point
Assigns button(s) to activate the pre-selected (registered) AF point.
  1. Assist button + AF point selector
  2. Assist button
  3. Switches only when the assist button is ON
19 Lens AF Stop Button Function
Changes the function of the AF stop buttons (only available on IS super-telephoto lenses.
  1. AF stop
  2. AF start
  3. AE lock while metering
  4. AF point: Manual Auto, Auto Center
  5. ONE SHOT AI SERVO
  6. Image Stabilizer (IS) start
20 AI Servo Tracking Sensitivity
Slow sensitivities prevent the autofocus being changed by anything passing between the lens and the subject. The fast sensitivities are effective when you want to shoot quickly with subjects at different distances.
  1. Standard
  2. Slowest
  3. Slow
  4. Fast
  5. Fastest